I've met Mark and discussed some of this stuff with him in person. He does have some strong opinions about things, as would be expected and he does believe that people should think more critically about things (including DIR) than they do. Nothing insane about that, although his webpage does come across as a rant.
He also, for various reasons, has a legitimate bone to pick with RGBM and Bruce Wienke. There is a bit of history to this but what he told me that he's discovered in his deep diving experience that the RGBM paradigm seems to break down in increasingly nasty ways on dives deeper than about 100m. I'd say given the number of really deep dives he's done, that he's in a pretty good position to point out what works and what doesn't work in terms of deco and gasses on those kinds of dives. I'd say, in fact, that he's in a better position to know it than some people with considerably bigger opinions about it. In any event, what he told me is that up to about 100m divers seem to be able to "get away" with using RGBM but that on dives under 100m using it would be insane to do so. One of his biggest bones to pick with the whole DIR paradigm seems to be that certain people with big opinions are wrong (as he sees it) about certain things (particularly about deco) and are completely unwilling to learn from the divers who know this and are completely unrepentent in this support of potentially dangerous practices, like using RGBM for deco.
I'll just disclaimer this by saying that this is what he told me and that I'm not one of the people with enough deep diving experience to know one way or the other. I, therefore, have no opinion about it but I have a sense that Mark is one of the few people in the position to really know.
R..
(Or do a 250 metre dive using RGBM before it had really been checked out, or dive using a modified Russian submarine escape system as a rebreather, or any of the other stuff you'll find if you check him out).
